Nicknamed the “prince of darkness,” Novak was both widely read and feared by Washington’s political elite. He began his famed column “Inside Report” with Rowland Evans in 1963, continuing as a duo until the latter’s retirement in 1993. Novak kept the column going until he was diagnosed with a brain tumor in July 2008.

Outside the Beltway, Novak was a familiar face to millions who watched him on CNN’s political chat shows like “Crossfire” and “The Capital Gang.”

In interviews with POLITICO, friends and colleagues remembered Novak on Tuesday as a tough competitor with a warm heart — or, as CNN political director Sam Feist summed him up, “a damn good reporter.”

“He wanted to know facts and he cultivated sources, and his career that spanned some 50 years in Washington, he may have been the best sourced reporter in Washington through many of those years,” said Feist, who first worked with Novak as an intern in 1989.

Bloomberg News executive editor Al Hunt, who sparred with Novak on air, said that “he leaves behind a big footprint.”

“He was wrong on everything, but we had such incredible fun,” Hunt recalled wryly, a catch in his voice. “Bob couldn’t have been a lawyer or a professor — you can’t imagine Bob as anything else besides the kind of hell-raising journalist that he was. Bob didn’t hide his views as a dyed-in-the-wool conservative. But he was incredibly hard on hypocrisy from the right. He never cared much that he wasn’t invited to White House dinners, even by Republicans — it was almost a point of pride.”

Hunt added: “He had a hell of a run: 50 years at the top of his game in Washington.”

Veteran journalist Jack Germond said that despite being “at opposite ends of the political spectrum,” Novak was a “good friend.”

“Bob was very supportive of moderate Republican candidates and he gradually changed,” said Germond, who recalled once finishing a large jug of wine with his fellow reporter before Novak gave a lecture on supply-side economics.

Jules Witcover, who co-wrote a political column with Germond for 24 years, spoke to POLITICO from Bethany Beach, Del., a spot where he often ran into Novak on summer vacations.

“First of all he was a great reporter, probably the most diligent and thorough reporters I’ve ever encountered,” Witcover said. “His politics was not what I shared but I always had a great admiration for his diligence and his honesty. He was also a great personal friend of mine.”

In the early days, Witcover recalled, it wasn’t apparent what Novak’s politics were. “And considering that he was identified so much in his later years, particularly as a conservative,” Witcover said, “it was even more impressive that he was able to break stories from people who he didn’t agree with.”

Novak was prolific. He and Evans liked to include at least one new fact in each of their columns — and for a time that meant five days a week. In addition to the column, the duo churned out the “Evans and Novak Political Report,” an inside dope newsletter that was the forerunner to the many electoral handicapping sheets that now exist.

And as he became a TV personality, Novak didn’t merely use his new platform to pontificate. In the pre-internet era, Novak turned to TV to break news that wouldn’t hold until his next column.

In his book, Novak recalls scrambling to get on CNN, for years his TV home, to reveal such information as Bob Dole’s selection of Jack Kemp to serve on the GOP ticket in 1996.

It was Dole who tipped Novak off, but of the two it was the supply-side Kemp not the budget-balancing Kansas who had the columnist’s affection. Despite years of tough Novak columns aimed his way, Dole recognized his tormentor’s influence and tried to win him over.

Dole wasn’t the only politico who tried to get on Novak’s good side. The columnist had a saying about political figures — you’re either a source or a target. A read through Novak’s “The Prince of Darkness” reveals a good many of both.

Serving as a source helped win protection — a Washington fact of life Novak embarrassingly copped to in his book — but as the years went on he became more ideological and less concerned about not offending those who fed him news items.

In his early days, Novak was a Rockefeller Republican. But he moved right on both fiscal and national security issues during the Cold War and as the New Right began to take off in the late ‘70s. He would also grow more staunchly conservative on social issues, and was inspired in part by his wife, Geraldine, to be more outspoken against abortion.

But being conservative didn’t mean being a Republican to Novak, who was openly contemptuous of many politicians and the general idea of blind partisan loyalty.

Recalling how Pat Buchanan had defended President Ronald Reagan’s support for higher taxes on “The McLaughlin Group,” Novak wrote in his book that, for Buchanan, “journalism was a temporary expedient, not a life’s work as it was for me.”

Novak recalled Buchanan telling him off camera: “I’m a party man.”

Such was not the case with Robert D. Novak, who while advocating for his principles, was never afraid to stick the journalistic shiv into any pol, right or left.

In his 70s and atop the Washington scene, he was as hungry for news and gossip as he was as a cub reporter for AP in Indianapolis.

Even after being diagnosed with brain cancer and officially retiring, Novak still followed the presidential campaign and wrote the occasional column. More than once during the campaign, he forced reporters 40 years younger to chase down his exclusives.

Through his conservative commentary on television and his column, Novak continued to maintain a presence inside and outside of Washington. A Washington original who earned his reputation in a very different journalistic era as well as in a very different nation’s capital, Novak nonetheless thrived in the cable news and Web eras because he continued to do what many columnists never do: work sources and break news.

Washington Times columnist and blogger Amanda Carpenter said that Novak was an inspiration for the conservative journalists who might not have been born when his early scoops rocked the capital.

“Mr. Novak will always be one my biggest personal heroes,” Carpenter said. “Although I only met him on a few occasions, he has always inspired me to work harder and more carefully than I otherwise might have in the age of fast and loose blogging. Many times while working my desk I’ve pictured Mr. Novak in my mind in his trademark three-piece suit, working his sources, checking his facts and cranking out column after powerful column.”

In 2003, after publishing the name of CIA operative Valerie Plame, Novak found himself in the glare of an intense spotlight. In the summer of 2005, he stormed off a set at CNN when he was about to be asked about his role in Plame’s outing. A federal investigation into the outing ultimately ensnared some of journalism’s biggest names, leading eventually to the conviction of former Vice President Dick Cheney’s chief of staff, Scooter Libby, whose sentence was later commuted by then-President George W. Bush.

While many top journalists and politicians paid tribute to Novak’s career Tuesday, MarketWatch media columnist Jon Friedman wrote that he wouldn’t be among them.

Novak “hid behind his journalistic reputation when he allowed himself to be used by the likes of Karl Rove, Scooter Libby and other members of George W. Bush’s inner circle,” Friedman wrote. “Novak was content to watch as the nation had to experience an agonizing investigation to explore what had happened.”

Novak announced just over a year ago that he had brain cancer and was retiring, thus ending the nation’s longest-running syndicated political column.

Kate O’Beirne, Washington editor of National Review, visited Novak at home about a week ago and said he was “infirm but alert enough to enjoy a visit.” She said he “fully appreciated what he was facing.”

O’Beirne said he cared more about shoe-leather reporting than pontificating. “He wasn’t a performer. He was a journalist. You never had a casual conversation with Bob. You’d say some throwaway line and he’d say, ‘What?’ He was always working.”

O’Beirne, his longtime fellow panelist on CNN’s “Capital Gang,” said he would want to be remembered as “hardworking, honest, no friends, no favors.” She said that at least until a few months ago, Novak would chat about current events.

“Maybe there’s a lesson here: He wasn’t that interested in current events,” she recalled of Novak’s final weeks. “He had been on top of everything, minute to minute. But he was more interested in going and talking about things that happened to him years ago, experiences he had in Illinois, events that had shaped his opinions.”

O’Beirne said Novak delighted in his grandchildren. “One got the sense that he was too busy for his own children, and he wasn’t going to let that happen again. He never failed to mention, ‘I couldn’t do any of this’ — the treatment, the operations — ‘without Geraldine.’”

Executive editor Fred Barnes, writing on the Weekly Standard’s website, said that Novak “terrified Washington.”

“It’s not too much to call Novak journalism’s last honest man in Washington,” Barnes wrote. “Ideologically, he was conservative, the more so the older he grew. He was quite up front about this. But he didn’t cover for his allies or mistreat his adversaries. If a conservative Republican disappointed him, Novak would let you know.

Following the news of his death, several Republican lawmakers offered their condolences.

House Minority Leader John Boehner (R-Ohio) said in a statement that Novak “made remarkable contributions in the field of journalism and to the American political landscape” and that “it is hard to imagine Washington without him.” Rep. Roy Blunt (R-Mo.) described Novak as “a good friend and dependable critic.”

“For more than half a century, Robert Novak explained the politics and the personalities of Washington to readers across the country through a mix of tireless shoe leather reporting and the kind of keen insight that can only be gained through years and years of dedication to a craft,” Senate Minority Leader Mitch McConnell (R-Ky.) said in a statement.

According to the Chicago Sun-Times — home to his column from 1966 until his retirement — Novak was born Feb. 26, 1931, in Joliet, Ill., and worked at the Joliet Herald-News and the Champaign-Urbana Courier while a student at the University of Illinois. He served in the U.S. Army during the Korean War before going to work for the Associated Press, which ultimately led him to Washington in 1957. He moved to the Wall Street Journal in 1958 and began his column with Evans five months before John F. Kennedy was assassinated in Dallas.

Andy Barr and Abby Phillip contributed to this story.